//https://leetcode.cn/problems/combination-sum-iv/

class Solution {
public:
    int combinationSum4(vector<int>& nums, int target) {
        vector<double> dp(target + 1);
        dp[0] = 1;

        for (int i = 1; i <= target; i++)
            for (auto e : nums)
                if (i >= e) dp[i] += dp[i - e];


        return dp[target];

    }
};